Safety device for air bombs



Dec. ,14, 1948. E. 1. LINDMAN 2,456,239

SAFETY DEVICE FOR AIR BQMBS Filed NOV. 5, 1941 //7K: 16 1 *2 zi I /0 M0 I /5 Patented Dec. 14, 1948 UfN-i TEE. S TATES PAT E N T O F Fl-C E Application November 3, 1941; Serial Nd-417,728 ImSwe'den Octoberfl, 1940 Section 1,.Public Law 690, August 8, 1946 Patent expires parts, which renders it very insensitive-t roughhandling and .causesitto function .very precisely and reliably.

Embodiments of bombsrin a-ccordance with this invention are shown in the annexed drawing.

Fig. 1 shows -a-longitudinal-seetion through .the igniting I device in thenoseof i the bomb-havin a safety device in accordance with this invention.

'Fig. 2 shows a detail of the-igniting device seen from above in Fig. 1.

its: 3 "shows, on aiarger -scale-,=-a-sectionthrough a modlfied' igniting device virith a safety device in accordance with this invention.

Fig. '4 shows -a-section on -theline IV- IV in Fig. 3.

Finally, Figs. 5 and 6 show modifications in views similar to Fig. 4.

Reierring now to Figs: 1 andz- 'o'f the-drawings, a' central tube -2 for-instance or metal; extends through-the whole length-- of-th'e bomb'which may be made-of-concret'e.

In the tube 2 a suitable charge is arranged. For igniting this charge, either by direct shook action or by means of an igniting charge (primer or fuse) and/ or an expelling charge (detonator) a firing pin In is arranged in the forward portion of the tube 2. In the embodiment shown, this pin is displaceably journalled in a plug Ma screwed into the front end of the tube 2, and to the pin plate II is secured which upon impact against the ground drives the pin l0 inwards and thus ignites the ind cator charge. A safety cap #2 may be provided to protect the pin during transportation.

A safety pin l3 having an ejector spring 30 is inserted through a hole in the body of the firing pin l0 proper and abuts against the free end of the neck Me of a plug IE to lock the firing pin. The safety pin l8 has a hole 24 for a safety wire to be secured to the airplane. The pin it may October 7, 1960 .of'the firing pin l0.

be: turned (rotated) in two planes at right angles to each other, viz. firstiyby turning the firing-49in iil in the plug it and secondlyby turningnthespin iii-around its own axis. Thus, itisualways pessib ie to-turn this pin so that the hole-lil- -andathe safety wire inserted therein is in theilongitudinal direction of the wire by means of which i-the safety wire is secured to the airplane sopthat th'e safety wire is'not subjected to any substantial bending stresses when the bomb is thrown. In other words, the safety wire maybeso pla'ced that it is extractedsubstantially in the longitudinal direction of the hole-24. A=nutl5se1=ves to support the spring Iii-abutting against .a -flange This spring serves to keep the firing pin in itsforward position-during -the free fall of the bomb through the air, in spiteidf the resistance set bytheair. The-firingmechanism just described is particularly suitable for heavy bombs.

The striking plate ll whichm-ay be plane-ior curved, efifects a pe'rfect firing action also when the-bomb strikes soft ground, water-or snow.

In-Figs. 3 and 4, the. bombi alsohas-a-iplug'l' l screwed into the-nose-end of the-tube-Z. Thetpllgg M-has a channel in which.afiring-pinslill moves. This pin should'be very-light and isconneotefd with a striking plate .I l and also -with'=aneye 2ll for hanging the bomb vertically in the iaiirr ilane. Theeye 20 may be screwed into a threaded of the-pin l 0 and clamps :theplate =-H tothe -bddy of .the firing pin.

A spring 15 is arranged between-the plug and the=.plate H.

Between the-plug and the-plate 'a safety device is normally provided which-in this-emboiib ment consists of two strips or pieces 2|, 22 of sheet metal. The piece 2| is bent at 23 and into this bend one edge of the piece 22 is inserted. When the safety device is applied to the bomb, the two pieces 2|, 2?. are bent towards each other resiliently. Just opposite the bend 23 they are united by a headed pin i311, which extends loosely through holes of the pieces and has a hole 24, into which a locking wire 25, for instance, a piece of piano wire. is inserted. This wire has an eye or loop 26 into which an iron wire or the like is inserted which is secured to the device for hanging the bombs in the a rplane.

The device just described acts as follows:

For dropping the bomb the aviator extracts a bolt or the like passing through the eye 20 so that the bomb begins falling. initially with its tail foremost. Becau e the wire 25 is secured to the airplane, it is extracted from the hole 24,

when the bomb drops. Immediately after this, the two pieces 2|, 22 spring apart automatically and are flung away from the bomb so that it is now armed with its safety device removed. It is evident that the axis of the hole 24 may be set in two planes at right angles to each other, that is to say: by turning the pieces 2|, 22 on the neck of the plug 14 and also by turning the pin I30. in its hole. Consequently, it is easy to adjust the position of the hole 24 in such manner that the wire 25 is in straight line with the wire secured to the airplane and consequently is always extracted in its longitudinal direction from the hole 24, whether the bomb is hung horizontally or vertically. Consequently, the bomb may be dropped without disturbances and the wire 24 is not subjected to any substantial bending stresses, when the bomb is dropped.-

In the safety device shown in Figs. 3 and 4 the .pieces 2|, 22 of sheet metal may be made of one integral piece 30 as shown in Fig. 5. In this case the legs of said safety piece spring apart at the release. It is also possible to arrange .a separate helical spring 3| between the parts of the safety device, for instance around the pin 13a as shown in Fig. 6, to press the parts of the safety device apart at the release. In such case the parts of the safety device need not be resilient.

What I claim is: 1. In an air bomb in combination, a firing pin turnably fitting in the nose of the bomb, a

striking plate on said firing pin and projecting in front of the nose of said bomb, a primer, a spring ,normallyholding said firing pin at a predeter- =mined distance from said primer and yielding at a predetermined minimum pressure higher than the maximum pressure effected by the air when the bomb falls through it, a safety clip comprising two fiat resilient plates between said striking plate and the bomb proper, said clip having an opening formed therein extending sembled and tending to spring apart automatically but normally being held in safety position by said safety pin, said safety pin having a transversely extending hole therein, and a locking wire extending through said hole in said safety pin,

;to be extracted in its longitudinal direction out of said hole when the bomb is dropped, said firing pin and safety pin being rotatable respectively in different planes so that the hole in the safety pin may always be in the longitudinal direction of said wire when the bomb is ready to be dropped.

2. In an air bomb, a body having an opening in its forward end, a firing pin slidably extending into said opening, spring means normally pressing said pin forwardly, a firing plate on the forward portion of the firing pin in spaced relation to the forward end of the bomb body, a safety clip rotatably engaging the firing pin between the bomb body and the firing plate, said clip having two flat parts of resilient material engaging opposite sides of the firing pin respectively with their fiat sides, one of said resilient parts having a turned over end forming a recess in which an end of the other part is located when assembled, the other ends of said parts having openings formed therein, a pin having a head on one end extending through said openings, said pin fitting said openings loosely and being rotatable therein, said pin having a transverse bore extending therethrough spaced from the head, and a wire extending into said bore, the fiat, resilient clip parts being resiliently deformed when assembled so as to exert pressure on each other and the pin head and wire at opposite ends and on the firing pin at their middle portions, whereby when the wire is withdrawn from the headed pin the resilient clip parts spring apart and away from behind the firing plate, thereby arming the bomb.

EMRIK IVAR LINDMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 981,069 Currell Jan. 10, 1911 1,077,989 Maxim Nov. 11, 1913 1,271,029 Gathmann July 2, 1918 1,556,027 Ragsdale Oct. 6, 1925 1,632,147 Ragsdale June 14, 1927 1,963,451 Yurgen et al. June 19, 1934 2,108,019 Neukirch Feb. 8, 1938 2,108,818 Hufi et a1 Feb. 22, 1938 2,327,414 Firing Aug. 24, 1943 2,335,763 Imber Nov. 30, 1943 FOREIGN PATENTS Number Country Date 235,161 Great Britain Dec. 10, 1925 258,649 Great Britain Sept. 22, 1926 443,451 Great Britain Feb. 28, 1936 500,919 Great Britain Feb. 17, 1939 

